The Functional Refactoring Pass

This is an anecdote, not a data point, yet. I'm a firm believer in functional programming and I consider myself a `mostly functional` programmer. I use functional programming when I can, but when a side effect is required, I'll use it. I'm not a purist. Functional programming is supposed to have a number of advantages over imperative, procedural programming. The primary advantage is that there are provably no race conditions. You can trivially scale functional code to multiple threads and multiple processors. In theory, functional code is easier to reason about and easier to test because each function can be reasoned about and tested in isolation. In practice, functional code can become a maze of thunks and lambdas that many find difficult to read. Nonetheless, I prefer to reason about tangled lambdas than to reason about tangled state. I believe that functional code is easier for an LLM to reason about as well. I haven't proven this, but anecdotally it seems to be the case. In…